Objectives

The primary objectives of this analysis is to use ARIMA models to find if Photosynthetic Active Radiation is a more suitable explanatory variable to Net Ecosystem Exchange than salinity to forecast future Net Ecosystem Exchange of a scrub mangrove forest.

Methods

Site Information

TS/PH 7 is located 25.19080491, -80.63910514 up Taylor River mainly characterized by scrub mangrove vegetation of the -Rhizophora mangle- species. This is an established FCE LTER site within the Taylor Slough Watershed.

Satellite Image of TS/PH7 Site Photo 5 months before Hurricane Irma: Dr. Edward Castañeda and PhD Student Melinda Martinez Apr. 18, 2017 by Marbelys Garriga

Statistical Analysis

Photosynthetic Active Radiation (par; W m−2 day−1) will be incorporated to the forecast function of the ARIMA model after the temporal dynamics of NEE were adquired. The Augmented Dickey-Fuller Test will be used to test stationarity. Ljung-Box test will test for independece and finally the Akaike Information Criteria (AIC) of the model outputs will be compared to test for model fitness.

Results

ARIMA.NEE4 SALINITY MODEL

ARIMA.NEE4 SALINITY MODEL

ARRIMA.NEE5 PAR MODEL Table 1

Model df AIC
arima.nee2 18 704.7663
arima.nee5 10 683.6937
arima.nee4 9 700.7734

Discussion

Photosynthetic Active Radiation seems to be a better explanatory series of nee than salinity with a lower AIC as you can see in table 1.